CN1063988C

CN1063988C - Method and apparatus for preventing section of steel beam from being unparall

Info

Publication number: CN1063988C
Application number: CN95116293A
Authority: CN
Inventors: 罗兰德·克赖恩格尔; 汉斯-彼得·格里耶斯
Original assignee: Mannesmann AG
Current assignee: Vodafone GmbH
Priority date: 1994-10-19
Filing date: 1995-09-18
Publication date: 2001-04-04
Anticipated expiration: 2015-09-18
Also published as: DE59509444D1; DE4438822A1; CN1120980A; TW283100B; EP0707903A2; EP0707903B1; EP0707903A3; US5792418A

Abstract

A process for preventing nonparallelism from occurring when rolling beams on universal beam rolling trains by partial application of coolant to the beams. The coolant is applied to the underside of the web during the rolling process in order to create an approximately symmetrical temperature profile in the web. The invention also relates to the apparatus for carrying out the method.

Description

Avoid the method and apparatus of girder steel section nonparallelism

The present invention relates to a kind of by produce the method and apparatus of nonparallelism to the local supply coolant of girder steel girder steel section when avoiding in omnipotent beam mill unit rolling girder steel.

In omnipotent beam mill unit, after leaving finishing stand, often find that parallel flange twists, in the Federal Republic of Germany's industrial standard (DIN-Norm), be called nonparallelism (Unparallelitat), in English, be accustomed to being called " Widetop ".The feature that the girder steel section reverses in the cooling procedure is, first half flange is widened, and the Lower Half flange shrinks, thereby presents a kind of defective generally.If this girder steel can be sent in the follow-up straightener, then the nonparallelism of flange can be subdued to a certain degree in the straightener that after this adds.

As everyone knows, cooling device preferably is configured in after the beam mill unit, and is used to influence its institutional framework after rolling shedule.Also known cooling devices, they can implement local cooling to flange in the operation of rolling, so that influence the transition region between web and the flange, thereby influence the tissue characteristics (DE-OS 1452106) of cost.

A kind of rolling extraordinary section bar is made the method for thermal straightening by DE-A1-4009707 is known, after finishing stand is discharged, just adopt this method at girder steel.The also more known preceding flushing device of beam mill unit that is located at, they are used for eliminating the oxide skin of adhering to.The cooling effect that meanwhile brings then is undesirable.

As can be seen, the cause of rolling girder steel nonparallelism problem described above is, during the hot rolling girder steel, the roll continuous cooling water constantly flows into the epicoele of the rolling section bar that is keeping flat, and causes the one-sided cooling of web upside there in one or more universal rolling mills.Because the cavity of resorption of section bar contacts hardly with the roll cooling water, institute is so that girder steel produces buckling deformation, and this distortion can reach sizable degree, and consequently will take very big strength in follow-up straightener could be eliminated.

According to WO 92/19395, not only spray cooling water down to the web upside but also to the web downside.Because cooling water is trapped in the upside cavity, thereby can not address the above problem.

The objective of the invention is, problem and shortcoming at the above prior art exists propose a kind of method and make a kind of equipment of implementing the method, adopt this method can prevent the nonparallelism and the distortion of girder steel when rolling in universal rolling mill.

By the present invention's suggestion that achieves the above object, in the operation of rolling, apply cooling agent, so that in web, be adjusted into the temperature field of a near symmetrical at the web downside.Near at least one universal rolling mill, only in the steel beam web plate underside area, the coolant jet at the web downside is set.

Here the difference of method of being advised and existing known method is that it uses in the operation of rolling, and is used for the downside of local cooling web.Therefore eliminated the asymmetrical temp field in the web, this asymmetrical temp field is owing to the roll cooling water that does not enter the girder steel epicoele causes with adding control.This shows that can not obtain the even temperature field by disposable cooling behind last pass, this cooling must be carried out in the rolling pass of front in the operation of rolling.Adopt by measure of the present invention, rolled piece has substantially web temperature uniformly when finishing stand is discharged, and, have only very little thermograde along web thickness, thereby can accomplish at back to back cooling procedure flange keeping parallelism.

According to temperature that records at web upside and downside and the temperature difference of calculating thus,, adjust intensity of cooling by control coolant flow and/or supply sealing.For this purpose, surface temperature at web upside and downside is measured with measurement mechanism, and measurement result is imported computer system, and this system determines the Temperature Distribution in the rolled piece continuously, and determine the time point of supply coolant in view of the above, and in each rolling pass necessary water supply density.

Producing the characteristics that the equipment of the method for girder steel section unevenness has when avoiding in omnipotent beam mill unit rolling girder steel to the local supply coolant of girder steel is, vicinity at least one universal rolling mill, only in the steel beam web plate underside area, the coolant jet of aiming at the web downside is set.Adopt this nozzle arrangements, the cooling of web downside is just carried out in one or more passages of the operation of rolling, thus the strong cooling after having avoided discharging from finishing stand, and this strong cooling can cause occurring crackle and distortion.By the continuous cooling of coolant jet, can control the uniformity in temperature field targetedly, adopt rolling degree after cooling and thereby in the inner way that produces huge thermograde of web, be impossible acquisition this inhomogeneity.

Coolant jet preferably is located in the zone of reversible universal rolling mill.In the omnipotent beam mill unit of continous way during rolling girder steel, favourable way is that coolant jet is located in the milling train unit on a plurality of positions.

Proved already that suitable was coolant jet to be contained on the continuous jet rod of placing laterally to stagger each other, and arranging obliquely towards rolling direction.Can make cooling agent that big as far as possible coverage rate is arranged like this, thereby can obtain very strong cooling effect.

If by another feature of the present invention, each coolant jet can switch on or off respectively, no matter is the width of film-cooled heat then, or the supply density of cooling agent, can be controlled.

According to a feature of the present invention, can use coolant jet with figure or oval jet graphics, also can use the coolant jet with flat nozzle by another feature, this flat nozzle can be aimed at the girder steel section by means of a rotating adjusting device.

In equipment by method of the present invention and enforcement the method, influencing structure organization, to make it to have corresponding metallurgy characteristic be not important content, importantly in web, maintain a temperature field of symmetry substantially with the flange depth of parallelism that therefore obtains motivatedly.Adopt measure of the present invention to accomplish this point with simple method, so can obtain better product quality on the one hand, reprocessing in straightener and required expense can drop to minimum level on the other hand.

Embodiments of the invention are represented in the accompanying drawings, and are illustrated hereinafter.Wherein:

The arrangement architecture of Fig. 1 coolant jet on jet rod;

Fig. 2 schematically illustrates the side view of jet rod position;

The configuration of Fig. 3 two coolant jets on jet rod;

The injection of the steel beam web plate downside that Fig. 4-6 width is different.

Fig. 1 has represented three jet rods 1,2,3, and they link to each other with water pipe 5 by slide-valve 4, are provided with slide-valve 6 in the water pipe 5 equally.The nozzle 8 that some lateral alternates always is housed on jet rod 1,2,3 in couples and tilts towards rolling direction 7, and they are in different lateral attitudes with respect to rolling direction 7.By means of slide-valve 4, by switching on or off each jet rod 1 or 2 or 3 respectively, can handle different coolant jet 8, thereby can change the width and the supply density of cooling agent.

Fig. 2 has schematically illustrated a refrigerant injection bar 1, and it is below roller plane 9, in the front of the universal rolling mill of representing with label 10.As seen from Figure 2, coolant jet 8 tilts towards rolling direction 7, thereby cooling agent stream is sprayed on the downside of web in face of rolling direction.

Fig. 3 represents the configuring condition of two coolant jets 8 on the jet rod 1 that is designed to tubulose.Nozzle edge 11 is rotary (shown in Fig. 3 left sides), so the width of each refrigerant injection and coverage rate can adapt to the groove width of girder steel.By view A (right-hand part of Fig. 3) as seen, coolant jet is contained on the jet rod (feed pipe) 1 with staggering each other, and cooling agent is aimed at girder steel with different angle [alpha] and β.Therefore on girder steel, be adjusted into big as far as possible cooling agent supply area, and thereby obtain a kind of strong cooling effect.

Girder steel

12,13 that Fig. 4 to 6 expression width is different and 14 cross section.As seen from Figure 4, it is just enough that two coolant jets 8 that laterally stagger mutually are set, and as the nozzle on the jet rod represented among Fig. 11, they are enough to spray to the whole width of web 15.For the girder steel 13 of the width maximum that schematically illustrates as Fig. 5,3 pairs of coolant jets 8 have been used; Configuration among this situation and Fig. 1 on the jet rod 3 is identical.The girder steel 14 of medium-width uses 2 pairs of coolant jets to spray, and the jet rod 2 among this situation and Fig. 1 is suitable.Installing is the flat nozzle with turn adjusting apparatus in this embodiment, and they can the most advantageously adapt to the various width of web 15.Obviously, also can use many jet rods simultaneously, that is to say, for the more coolant jet of this width needs of web, for example in order to improve intensity of cooling.

Claims

1. produce the method for girder steel section nonparallelism when avoiding in omnipotent beam mill unit rolling girder steel to the local supply coolant of girder steel, it is characterized by: in order in web, to set up a temperature field that is similar to symmetry, in the operation of rolling, only cooling agent is sprayed on the web downside, according in measured temperature of web upside and downside and the temperature difference of calculating in view of the above, by control coolant flow and/or supply density, adjust the intensity of cooling of cooling agent.

2. produce the equipment of girder steel section nonparallelism when avoiding in omnipotent beam mill unit rolling girder steel to the local supply coolant of girder steel, it is characterized by: near at least one universal rolling mill (10), only in girder steel (12,13,14) web downsides (15) zone, the coolant jet (8) at the web downside is set.

3. according to the described equipment of claim 2, it is characterized by: coolant jet (8) is located in the zone of reversible universal rolling mill (10).

4. according to the described equipment of claim 2, it is characterized by: coolant jet (8) is located at a plurality of places of continous way universal mill unit.

5. according to the described equipment of claim 2 to 4, it is characterized by: coolant jet (8) is located on the jet rod (1,2,3) of continuous placement and laterally staggers mutually, and tilts towards rolling direction (7).

6. according to the described equipment of claim 2, it is characterized by: each coolant jet (8) can be connected respectively and cut off.

7. according to the described equipment of claim 2, it is characterized by: can use coolant jet (8) with circle or oval jet graphics.

8. according to the described equipment of claim 2, it is characterized by: coolant jet (8) is the flat nozzle that has rotation adjuster.